this account, they are not refponfible for the accuracy of every statement or the juftnefs of every opinion contained in their books, they mean to infert nothing, which is not recommended by the appearance of novelty, ingenuity or utility. They are fatisfied the feries of papers, which they have laid before the public, including the prefent pamphlet, will be found to contain, not only fome highly interefting articles of natural history, but valuable hints and facts refpecting feveral of the leading parts of husbandry. Though in many inftances the methods of cultivation in ufe may be the beft which, confidering the capital of the farmer, the comparative value of labour and land, and other circumstances, can be adopted, yet in other inftances much room exifts for improvement. It cannot be doubted that information conveyed in printed works may be fubfervient to the correction of errors in opinion and practice, and to the diffufion of good modes of culture.

Those who take the trouble to prepare this publication are aware, that in this fubject theory is good for nothing till fanctioned and confirmed by experience; that old modes of husbandry ought to be held in refpect and changed with caution and moderation, and that farming by teoks merely, is juftly derided. At the fame time they are convinced that Agriculture

derives aid from the difcoveries and labours of the philofopher, the naturalist and the chemift; that principles grow out of practice; and that inquiry is the road to improvement. They have no more refpect for a bigoted attachment to injudicious cuftoins, than for a rafh fpirit of innovation; nor can they aicribe wifdom or modesty to thofe, who think their own practice comprifes all that is or can be known, and refufe to read printed documents, which relate the obfervations and experiments of others.

The different refults of the experiments on potatoes, as related in the two firft papers of this collection, will natur

•«Nor thou the rules, our fathers taught,

defpife,

Sires by long practice and tradition wife." Sotheby's Tranf.Georgics. b.i.v.115.116.

ally excite attention, and probably put thofe, who are not satisfied about planting large or fmall potatoes, eyes, or cuttings, upon further trials of the different methods.

The obfervations on the progrefs of vegetation in the next paper, comprise a part of natural hiftory, which is evidently applicable to the ufe of agriculture. A fufficient number of notices of this kind would afford the best fort of almanac for regulating feed time. It is hoped gentlemen in various parts of the country will frame and fill up fimilar tables. Where the feveral trees, fhrubs and plants, here mentioned, are wanting, they may be fupplied by other kinds. The field or the wood will compenfate the deficiency of the garden.

We publish a new confirmation and illuftration of Mr. Cooper's doctrine and practice, refpecting feds, as related in a letter of his in a former number, and it is to be wifhed that every farmer will endeavour to teft and be able to verify them for himself.

The sketch of foils and manures must be ufeful to all who would have the habit of difcriminating the feveral fpecies of each, and adapting culture accordingly; and the analysis of lime and marl requires fo much knowledge of chemistry only as can be learned and applied by the common farmer. The treatife on the culture and preparation of bemp being intended for the inhabitants of Canada, is of courfe applicable to our inftruction.

The efficacy of fult in curing clever is propofed to the ferious attention, and the careful experiments of farmers. The documents here publifhed will fhow how much reafon there is to expect it will be found highly beneficial; and the premium offered by the trustees, is added to other inducements, for giving it further trials.

The files of the Society contain a number of fets of anfwers to Agricul tural Queftions fent out by the trustees fome years ago. They delay making ufe of what they have, in hopes of more. Will farmers, into whofe hands they are put, favour them with their anfwers that they may proceed to give the public the information received either entire or digested? For this and

other affiftance in fulfilling their office, the truffees look not only to intelligent individuals, but to the agricultural aflociations in different parts of the ftate, to fome, or most of which they are already indebted; and to one for the firn document in this pamphlet.

In the name of the Society, the trustees repeat their requeft to these affociations for original communications, and their affurances of ability and readiness to publifh for their and the general benefit whatever novel, interefting or feasonable matter, they fhall put at their difpofal.

A difcourfe delivered before the Humane Society of the Commonwealth of Maffachusetts, at their femian ual meeting, June 12, 1804. By John C. Howard, 4. M. M. M. S. Boston. Sprague. 8vo. pp. 21.

THE interesting phenomena of refpiration, and the production of animal heat, have of late years clofely engaged the attention of philofophers; and the discoveries of the modern chemical fchool have much enlightened this curious and important fubject. But thefe phenomena, like most others of the animal economy, are ftill enveloped in an obfcurity which the most accurate obfervations and the most industrious experiments have not perfectly diffipated.

The learned Dr. Black remarked that animals which have lungs are warmer than all others; and that there is an intimate connection between the frequency of refpiration and the degree of animal heat. Hence he naturally fufpected, that the lungs inftead of being, as was then be lieved, a pair of bellows for cooling the body, were themselves the

He

producing caufe of heat. purfued and inveftigated this idea. Many others following him have difplayed fuch a multitude of facts to prove this opinion, that it has become the received doctrine through the learned world.

A few philofophers, either ftaggered by fome oppofing facts or attached to the old fyftem, ftill reject this theory, and offer in its place fome one, and fome anoth

er.

Among thefe we must clafs the author of this difcourfe ; whofe ideas appear to be in part novel, and partly coincident with the ancient opinions.

by him believed to be quite The origin of animal heat is diftinct from the refpiratory pro cefs; and dependant on a fubtle, incomprehenfible, and unintelligible principle.

Animated bodies, (says he,) from the nice and peculiar arrangement of their particles, poffefs the property of maintaining that action, which the first impulfe of motion commences, and of longer refifting the perpetual nifus for an equilibrium. Animal heat is an efrion of the exiftence of this diftinguishfect of this property, and is the crite ing characteristic. The fucceffive expanfions and contractions, then, of the animal fibres, conftitute thofe vibrations which we call life, and they are equally fame univerfal caufe, which first gave dependant upon the fame principle, the motion to matter. Vain and prefump tuous is the attempt to discover this principle, by anatomical investigation or chemical analysis; for its evanefcent existence waits not their refults, and the moment of research is but the fignal for its escape.

As thefe "fucceffive expansions and vibrations" are dependant on a principle, which the author thinks it improper to investigate, we cannot afk him for facts; and

we may be excused for declining the refutation of an unfupported opinion. But furely it might as juftly have been faid at once, as fome one has faid on another fubject, "That the animal heat exifts because the Creator has fo willed it."

After thus combating the idea that heat is derived from the lungs, the author proceeds to confider the ufe of refpiration, and commences with an account of the manner in which he conceives it to begin.

Immerged into the atmosphere (the animal at birth) immediate evaporation is the effect of the first contact of air upon its delicate surface. A fudden contraction is the neceflary confequence. This is the first stimulus, and like the electric with which it may be identified, it immediately pervades the whole fyftem, although we obferve it only, where fome obvious effect is pro duced. In confequence of this evaporation, the intercoftal mufcles are contracted, the ribs are raised, and the diaphragm is drawn down; thus is the cavity of the thorax enlarged, and thus are the lungs expanded. Then, and not till then, is the air admitted, and the cry which fucceeds is no more than the index of this occurrence. The undiquaque preffure of the atmosphere would preferve an equilibrium, and thus expanded would the lungs remain, did not the infpired air destroy the balance by producing evaporation, and there again exciting

contraction. The ftimulus is inftanta

neously propagated, and the abdominal mufcles with the diaphragm, by their reaction become the ready and efficient auxiliaries in the office of expiration. Thus the fucceffive application of the fame ftimulus produces the alternate expanfion and contraction of respiration, thus are the blood veffels on the

furface, and in the lungs fucceffively excited to propel their contents, and thus is life maintained by the reciprocal abstraction of its effential principle.

If we rightly understand this piece of theory, the author thinks

the caufe of the first contraction of the mufcles of infpiration to be evaporation from the furface of the skin which covers them; and that of the first contraction of the mufcles of expiration to be evaporation from the internal furface of the lungs. Suppofing the first to be true, the fecond is inadmiffible. For the lungs have no contractile power of their own, and there is no reason why the diaphragm and abdominal muscles fhould not be contracted by the propagation of the external ftimulus, as well as by the internal ; and as the former exifts first, it muft operate firft. Nor do we know any fact to prove that mufcles are dependant on each other for their powers. They are all dependant on the nerves.

But is

it true that evaporation is the caufe of the firft contraction of the muscles of infpiration? Fact fhows that it is not. For if an infant be covered at the inftant it emerges into the air, it will not the lefs infpire. On the contrary, when in the new born infant, the action of refpiration does not commence of itself, it is fometimes promoted folely by plunging the infant under warm water, where no evaporation can take place from its furface. fome remarks on the changes which air undergoes in the lungs, the theory is thus concluded :

After

The function of refpiration then is to originate, and maintain a certain motion of the animal fibre effential to vi

tality, and the effect is produced by the contraction from evaporation, excited by atmospheric air, which from its particular compofition, and the eafy and various change of its application, is peculiarly fitted for this purpose.

But it should feem, that the

originating a "certain motion of the animal fibre" were quite a ufelefs office for the lungs, if we believe, what is before afferted, "that the expanfions and contractions of the animal fibres, which constitute thofe vibrations we call life, are equally dependant upon the fame principle, the fame univerfal caufe, which first gave motion to matter."

We might adduce many facts, which make it appear improbable that evaporation from the lungs is the use of the refpiratory function. As this feems unneceffary, we will offer only one of the fimp eft. According to this theory, whatever increafes evaporation from the lungs ought to increase the facility of refpiration. As heat promotes evaporation, hot air fhould be better for refpiration than cold: But this is contrary to fact; for every one has felt that it is more laborious to breathe during the violent heats of midfummer, than in the cool breezes of autumn, or even the severest colds of winter.

on

"A few remarks" are occafionally made by the author " the received fyftem, which," in his language, "feems, if not to have fatisfied, almost to have filenced inquiry." He however prepares the way for an eafy and entire fubverfion of this formidable theory, by a bold affertion that the diftinctions of fenfible and latent heat were invented for the exigencies of their employers. We lament for the scientific reputation of our country, that such expreffions fhould be put forth by a literary and a medical character. General and unfupported affertions are not uncommon with us. They take their origin from

the licentioufnefs of political publications, with which our newipapers abound. But it should be remembered that philofophy demands the severity of argument and the accuracy of fact. The truth is, that the distinctive characters of fenfible and latent heat were observed by Dr. Black before the exiftence of this theory of refpiration; that many philofophers and chemifts have made experiments on this fubject, entirely diftinct from and without any reference to refpiration; that the whole body of modern chem-. ifts agree in the general experiments on this matter; and that fuch a number of clear and decifive facts and experiments have been made upon it, as fcarcely any other chemical doctrine poffeffes. We must believe that the author has not fufficiently advented to these things.

The difficulties attendant on an accurate examination of the gafeous fluids concerned in refpiration, have attracted some remarks. It is obferved that tho' a quantity of oxygen difappears in the lungs, there is no proof that it is abforbed by them. This is true; but it is alfo true, that we have no proof of the whole quantity being employed in the formation of water and carbonic acid gas.-Here we are for once forced to relinquish experiment and reafon from analogy. The process of respiration in many refpects resembles that of combustion. The latter cannot exift without air: nor can the former. They both vitiate the air which they ufe, and destroy its power of fupporting them. They alfo equally vitiate the air